While the basic LISA concept has changed little over the past 20 years,
advances in astrophysics and cosmology over this time have been dramatic.
Future missions such as JWST, Euclid, WFIRST and Athena will further
reshape the landscape prior to the LISA launch in the 2030s, as may
discoveries by gravitational wave detectors operating in other frequency
bands. These developments require us to periodically revist the LISA science
case, and identify new synergies with other observatories. For example,
Euclid and WFIRST are expected to detect dozens of very high redshift (z > 8)
AGN, revealing the high mass tail of the early black hole population, while
a suitably configured LISA mission could provide complimentary information
about lower mass systems at these redshifts. Closer to home, recent surveys
indicate that there are far fewer compact binary sources than originally
estimated, which may be the one time where having fewer gravitational wave
sources is a good thing as the foreground "noise" is reduced, while the
number of resolved galactic sources is essentially unchanged. I will discuss
these, and many other changes to the LISA science landscape, and consider
how they might impact the science case and the mission design.
[Preview Abstract]

As a response to the selection of the Gravitational Universe as the science theme for ESA’s L3 mission, ESA formed the Gravitational-Wave Observatory Advisory Team (GOAT) to advise ESA on the scientific and technological approach for a gravitational wave observatory. NASA is participating with three US scientists and one NASA observer; JAXA was also invited and participates with one observer. The GOAT looked at a range of mission technologies and designs, discussed their technical readiness with respect to the ESA schedule, recommended technology development activities for selected technologies, and worked with the wider gravitational-wave community to analyze the impact on the science of the various mission designs. The final report is expected to be submitted to ESA early March and I plan to summarize its content.
[Preview Abstract]

The European Space Agency (ESA) selected gravitational-wave astrophysics as
the science theme for its third large mission opportunity, known as `L3,'
under its Cosmic Vision Programme. NASA is seeking a role as an
international partner in L3. NASA is: (1) participating in ESA's early
mission activities, (2) developing potential US technology contributions,
(3) participating in ESA's LISA Pathfinder mission, (4) and conducting a
study of how NASA might participate. This talk will survey the status of
these activities. [Preview Abstract]

GRACE Follow-On will replace the Gravity Recovery and Climate Experiment
(GRACE) mission, which has been measuring Earth's gravity field since 2002.
Like GRACE, GRACE Follow-On will use a microwave link as its primary
instrument to measure micron-level changes in the 200km separation of a pair
of satellites in a following polar orbit. GRACE Follow-On will also include
a 2-way laser-link, the Laser Ranging Interferometer (LRI), as a technology
demonstrator package. The LRI is an NASA/German partnership and will
demonstrate inter-spacecraft laser interferometry with a goal of 10 times
better precision than the microwave instrument, or about 90 nm/$\surd $(Hz)
between 10 and 100 mHz. The similarities between the LRI and a single arm of
Laser Interferometer Space Antenna (LISA) mean many of the required
technologies will be the same. This talk will give an overview of the LRI
and the status of the LRI instruments, and implications for LISA. [Preview Abstract]

A space-based gravitational wave observatory is required to access the rich array of astrophysical sources expected at frequencies between 0.0001 and 0.1 Hz. The European Space Agency (ESA) chose the Gravitational Universe as the science theme of its L3 launch opportunity. A call for mission proposals will be released soon after the completion of the LISA Pathfinder (LPF) mission. LPF is scheduled to start science operations in March 2016, and finish by the end of the year, so an optimized mission concept is needed now. There are a number of possible design choices for both the instrument and the mission. One of the goals for a good mission design is to maximize the science return while minimizing risk and keeping costs low. This presentation will review some of the main design choices for a LISA-like laser interferometry mission and the impact of these choices on cost, risk, and science return.
[Preview Abstract]

Before the end of the decade, both LIGO and Pulsar Timing Arrays are expected to make the first detections of gravitational waves, and in all likelihood will have started the compilation of the first gravitational wave catalogs. Both LIGO and Pulsar Timing Arrays observe source populations that radiate in the LISA band at other points in their evolutionary history. In this talk, we'll discuss how early detections of supermassive black hole binaries (by PTAs) and ultra-compact binary mergers (by LIGO) will be important players in understanding the scope of LISA science. [Preview Abstract]

On December 3rd at 04:04\,UTC, The European Space Agency launched the LISA Pathfinder satellite on board a VEGA rocket from Kourou in French Guiana. After a series of orbit raising manoeuvres and a 2 month long transfer orbit, LISA Pathfinder arrived at L1. Following a period of commissioning, the science operations commenced at the start of March, beginning the demonstration of technologies and methodologies which pave the way for a future large-scale gravitational wave observatory in space.
This talk will present the scientific goals of the mission, discuss the technologies being tested, elucidate the link to a future space-based observatory, such as LISA, and present preliminary results from the in-orbit operations and experiments.
[Preview Abstract]